I really doubt this changes much on how the team works. Maybe Hahn will just be in charge of the more day-to-day stuff as GM, but KW has ultimate say in major personnel moves. Much like the Bulls with GarPax.

No way this happens. Why would Hahn be GM in name only if he doesn't have the ability to make the moves he feels are best for the team? The guy has had GM interviews the last few years and has reportedly turned down offers to be a GM elsewhere. If he's staying, he's staying to be GM and not KW's puppet.